Læknablaðið - 15.10.1994, Blaðsíða 55

LÆKNABLAÐIÐ 1994; 80
399
Nýr doktor í
Magnús Guðmundsson, læknir í Gautaborg
varði doktorsritgerð í læknisfræði við Háskól-
ann í Gautaborg 19. maí síðastliðinn.
Ritgerðin heitir Clinical use ofblood rheology
measurements in rheumatology. Fer ágrip hér á
eftir.
The aim of this thesis was to evaluate rhe-
ological methods for clinical use in rheumatol-
ogy, to establish normal values for plasma vis-
cosity (PV) and whole blood viscosity (WBV)
and to study the significance of elevated viscos-
ity levels in plasma and whole blood of patients
with rheumatoid arthritis (RA) and giant cell
arteritis (GCA).
The group of healthy subjects included 148
blood donors, 34 volunteers and 20 heavy
smokers (>20 cigarettes per day). Altogether
225 RA patients and 31 GCA patients partici-
pated.
Viscosity measurements of plasma, serum
and whole blood were found to be reliable
tests, with low rnethod errors, when used as
routine rheumatological examinations. No age
or sex influences on the viscosity variables
were found. Neither were they influenced by
moderate smoking, whereas they were influ-
enced by heavy smoking.
The correction of BV to HC 40% by extra-
polation from a standard curve, establised by
concentration/dilution of samples from
healthy persons, was the best method of mea-
suring whole blood viscosity and separating
values of a group of blood donors from values
of a group of RA patients.
PV, BV and red cell aggregation (RCA)
were higher in RA patients compared with
blood donors. Patients with extra-articular
manifestations of RA had the highest values.
The results suggested a previously not de-
scribed difference in rheological properties of
the blood between patients with different ex-
tra-articular manifestations that are not re-
flected by conventional laboratory tests.
Significant correlations with combined clin-
ical variables were only found for PV and not
for ESR or CRP in RA patients followed dur-
læknisfræði
ing parenteral gold therapy. PV discriminated
significantly better than both ESR and CRP
between active and inactive disease.
In the group of GCA patients before gluco-
corticoid treatment, all patients had increased
values of PV and ESR. No significant differ-
ence was observed in any laboratory variable
between the clinical subgroups of GCA. The
flare-up risk within the first year on a fixed
therapeutic schedule could be reduced using
the ESR and PV as indicators for a prophylac-
tic increase of the glucocorticoid dose. The
critical value of PV coincided with the upper
normal value, whereas the critical ESR value
was within the normal range. This made PV
preferable to ESR as a laboratory test in the
monitoring of therapy in GCA.
Conclusions: The results have shown that
PV and WBV are reliable tests in rheumat-
ological practice and both tests are significant-
ly increased in RA and GCA compared with
healthy controls. PV is of significant value in
the monitoring of therapy in patients with RA
and GCA. The potential role of PV, WBV and
RCA in pathogenetic studies of these and oth-
er rheumatic diseases warrants further explo-
ration.
Key Words: Blood viscosity, plasma viscosity,
haematocrit, red cell aggregation, rheumatoid
arthritis, giantcell arteritis, polymyalgia, blood